


Fire & Magic

by h0i_im_dennis



Category: Undertale (Video Game)
Genre: M/M, This is my first fanfic lmao
Language: English
Status: In-Progress
Published: 2020-05-01
Updated: 2020-10-03
Packaged: 2021-02-23 07:14:06
Rating: Teen And Up Audiences
Warnings: Underage
Chapters: 18
Words: 3,952
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23941012
Author URL: https://archiveofourown.org/users/h0i_im_dennis/pseuds/h0i_im_dennis
Summary: this is when they are all teenagers. where the school is (ye i made a school to force them to learn) i dunno but it exists somewhere. also they are in the underground, its after the war but not really? idk basically i strayed too far away from undertale’s original cannons and now you have this. also it may mention suicide, so heres a trigger warning for everyone. also maybe smut. idk i need to decide.I DONT OWN UNDERTALE. ALL CHARACTERS BELONG TO TOBY FOX UNLESS OTHERWISE STATED.thanks-kris
Relationships: Grillby/Sans (Undertale), Sansby
Comments: 14
Kudos: 14





	1. Chapter 1

**Author's Note:**

> this is my first fanfic so don't judge (too harshly bc i know i need constructive criticism) please also if theres going to be smut i’ll update the summary and the warnings bc it'll be underage.

September

(september is in sans’ pov)

September 9th Monday 20XX  
It was a normal first day of school. The teachers were pretending to be nice, giving all of the “beginning of the year” easy crap. But then he walked in. A transfer student we were told. He sat down next to me. He’s fucking hot. Not in that way, just that he’s made out of literal fire. He shook hands with me and Tori, who sits on the other side of him. Told us his name was Grillby. Asked me how it was, being one of the last skeletons. Told him tibia honest, I barely notice. Tori groaned at the shitty pun, but he laughed. I introduced myself and Tori. A few of my other classmates came (Asgore, Catty and Bratty to be specific). I invited him to sit with me at lunch. He looked surprised, but accepted. I showed him around the school and told him the best places to hide in case he escaped detention. But then of course Undyne had to yell out Grillby and Sans sitting in a tree, k-i-s-s-i-n-g. I threw her over the gate of the yard. After that, it was business as usual. Papy tried to stop me from adding ketchup to the spaghetti, Gaster didn’t return until 10:00 pm, and I finished my homework. And of course, now I’m writing in this journal that was Gaster’s present for me for this first day of school.

**Notes for the Chapter:**

> never


	2. September 10th Tuesday 20XX

**Summary for the Chapter:**

> idk just a normal day i guess

September 

September 10th Tuesday 20XX  
Second day of school. Grillby asked if there was anywhere on the roof that had a good view of the Underground. We skipped 2nd and 3rd period just by looking at the town from the roof. Nothing special, but when we were getting down, he slipped. I grabbed his hand. I’m not sure why, but we both blushed. I didn’t even think it was possible for something(one) made of fire to blush. We went to lunch, neither of us looking the other in the eye. It was… strange, to say the least. I took out the spaghetti that Papy made for me. It was a lot better than usual. I have a sneaking suspicion that Gaster helped him with it. But besides those few strange things today was a normal day in every way.

**Notes for the Chapter:**

> gonna


	3. September 11th Wednesday 20XX

**Summary for the Chapter:**

> i dont think sans is ok

September 11th Wednesday 20XX  
I returned to school with a weird spring in my step. Even Temmie noticed, and she didn’t even know that Grillby existed until today. So I continued to walk (skip? idk) all the way to my class. Tori stopped me in the hall right before I entered home room and asked if I was ok. I responded with a fuck yeah, even though I had never done that before. She looked at me strangely, but let me skip (walk?) the rest of the way. Grillby was reading a book on magic, so I simply yeeted it out of the window. I told him that it was no good to just read about magic, that you have to experience and see magic work. As an example, I took the book I yeeted out the window and brought it back. He looked amazed, but I told him that not all magic was that flashy. That there’s some that are pretty low key. Just like the magic that allowed him to read a book and not destroy it, or the magic that lets me have facial expressions. And so I tried to help him experience magic. I even lifted him in the air, and almost dropped him too. Then we just went to our classes. At one point, I thought he might of been staring at me but I’m sure it was just a trick of the light. Everything after that was normal. Papy tried to make us eat his special cold spaghetti, but I decided that I wouldn’t. And a good thing to, because I heard Gaster suffering later when he tried the spaghetti.

**Notes for the Chapter:**

> give


	4. September 12th Thursday 20XX

**Summary for the Chapter:**

> assembly day because someone was being stupid

September 12th Thursday 20XX  
We had an assembly today. Apparently someone went into the school bell tower, and they got hit in the head by the mallet that they use to sound the bell. And it sounded like if it was a new kid who got dared to stay up there. I asked Grillby if it was him. He said he was a dumb ass, bit not that dumb. I took that as no. We took the rest of the day off from classes, seeing as nothing was going to be taught. It was a good day, as far as good days go. Gaster finally let Papy use the oven with no supervision. The spaghetti burned.

**Notes for the Chapter:**

> you


	5. September 13th Friday 20XX

**Summary for the Chapter:**

> they start to text

September 13th Friday 20XX  
I got a random text message from someone I didn’t know asking if I was Sans. I replied by saying yes, but who the fuck are you? The reply came fast. I’m nobody, who are you? nah, I’m kidding it said I’m Grillby from school. We chatted for a bit, but then he asked if I could help him with something after school. I said bitch, let's do it now. So we met a few blocks away from Waterfall. He was going to say something, but Undyne popped out of nowhere and said SNEAK ATTACK YOU FUCKING NERDS. I simply floated her back into the air and to her to try not to be insulting. Needless to say, she just threw some spears at me. I had to shove Grillby out of the way and then deflect them. Then I saw him, holding on to the bridge, nearly falling off. And I thought wow, this is the second time I’ve had to save him from falling. And then I thought fuck I can’t lose him. So I took all my magic and just flipped him into the air and caught him. It was an awkward position and I dropped him. It was an awkward walk home to say the least.

**Notes for the Chapter:**

> up


	6. September 14th Saturday 20XX

**Notes for the Chapter:**

> in which i artificially add my favorite band (?) in the story

September 14th Saturday 20XX  
Today the diner in the center of Snowdin was hosting a karaoke night. So I, being the great friend I am, dragged Grillby to it. He didn’t want to sing, so I did. I requested a song that I got by hacking into the music stations that humans have. I asked for The Good Part by AJR. (lyrics right there⬇️)

One two three four  
One two three four  
One two three four  
Have I done my best here, or  
Will I be here next year, or  
Are these my best years yet?  
Was looking forward to  
Being important but  
I'm not important yet  
If you put this scene on a movie screen  
Is it called a helping hand?  
If the world gets me  
Where I'm supposed to be  
Will I know I've made it then?  
It's so hard  
Can we skip to the good part?  
One two three four  
One two three four  
If there's a good part then  
I hope it's not far 'cause  
I thought it'd be today  
I napped on campus and  
I smoked that damn six bud  
It didn't feel so great  
If you put this scene on a movie screen  
Is it called a helping hand?  
If the world gets me  
Where I'm supposed to be  
Will I know I've made it then?  
It's so hard  
So can we skip to the good part?  
One two three four  
One two three four  
One two three four  
One two three four  
These things take time  
Mom and dad they have a good life  
But what am I gonna do with mine?  
These things take time  
Mom and dad they have a good life  
But what the hell am I gonna do with mine?  
I, of course, ~~embarrassed myself~~ did great. But Grillby had a weird expression on his face. So I promptly shoved him on the stage. And then he just walked off it, dragged me outside and told me no that he would not sing in front of people. So I left it at that and took him to a shop to get some sweet buns. Besides that, it was pretty nice.

**Notes for the Chapter:**

> never


	7. September 15th Sunday 20XX

**Summary for the Chapter:**

> and i quote, “it was an eventful day”

September 15th Sunday 20XX

It was a boring day. Gaster told us we should stay home where he could keep an eye on us. He said we couldn’t invite anyone over, so I just spent the entire day texting Grillby and we both were complaining about life in general when I had an idea. I told Grillby to meet me at the shop that we bought sweet buns from. He just said in how long. I answered as soon as possible. So I use a “short cut”. I really just teleported over there. Surprisingly, I saw him just running over there like it was nothing. I told him that he could have just asked me to teleport him over. He said that it felt lazy. My response? That's the point. A few minutes later Gaster came running and yelled at me for leaving without saying anything. I asked him how he found us and he said that I should get a password for my phone. So I got dragged home and sent to my room for sneaking out of the house. It was an eventful day.

**Notes for the Chapter:**

> gonna
> 
> also i just realized i contradicted myself. the first sentence was “it was a boring day” and the last sentence was “it was an eventful day”. well im a lazy fuck so i’ll leave it.


	8. September 16th Monday 20XX

**Summary for the Chapter:**

> grillby wasnt at school. call the motherf*cking cops

September 16th Monday 20XX

Second week of school. The teachers actually started being strict, most likely how they normally are. I got some homework because the fighting teacher, Gerson, said I was using improper fighting form and that I had to work on it for at least 30 minutes. And it didn’t help that I challenged him to a fight to see who was correct. I noticed that Grillby wasn’t at school though. I texted him and he said he had a cold from not wearing a proper jacket. So, being the great friend I am, I skipped school and went to his house to check on him. I knocked on his door and someone else answered. She looked like Grillby, but green. I told her that I was Grillby’s friend from school. She looked skeptical, but let me in. She told me that his room was the first to the left. So I knocked on the door and said hey,Grillby its Sans. A shaky voice told me to come in. Now, I don’t know how to tell when a person made of literal fire is sick, but his face was a slight blue color that couldn’t have been normal. Shit, I was scared. So umm, Grillby started to say, I have a fucking cold, and me being literal fire, its going to feel and look shitty. I mean, the look on your face! It seemed you were going into shock. Even after he tried to make some small talk, it was a bit awkward, because I knew it was my fault that he got the cold. It was a bit after noon that I left. He looked so exhausted, and so that's why I left. I’m hoping that perhaps he will be able to come back to school by at least Wednesday. It's sort of lonely without him. On that note, I guess it's time for me to go and eat dinner. I’ll write tomorrow.

**Notes for the Chapter:**

> let


	9. September 17 Tuesday-24 Tuesday 20XX

**Summary for the Chapter:**

> grillby is sick

September 17 Tuesday-24 Tuesday 20XX

(spoiler alert: Grillby didn't come to school any of the days. It was lonely. So I skipped. Again. 🙃) I would usually bring soup. The green flame girl (her name is Fuku) is actually Grillby’s cousin. She looked less and less suspicious each time that I visited. And on Wednesday, Papyrus asked if I wanted to bring his magnificent spaghetti over there so Grillby would feel better sooner. I simply told him that his spaghetti was so good, that his mind would explode, and him being sick would make that not very good on his brain cells. Papyrus said he understood, but that as soon as he’s not sick to give him some of his splendid spaghetti. It was fun, as fun as hanging out with a sick person can be any way.

**Notes for the Chapter:**

> you


	10. September 25 Wednesday 20XX

**Summary for the Chapter:**

> grillby goes back to school and a certain bean is happy

September 25 Wednesday 20XX

I went to school and surprisingly Grillby was able to make it to school without getting sick again. It was nice to have him around to talk to again (and I mean at school, because I’ve been talking to him). Everyone made such a big fuss, (especially the girls. I’ll never understand them) because he was sick for a week and they pretended that they actually gave a shit when no one else wanted to visit him when he was sick. When he finally made it to the seat I saved him he looked flabbergasted. (or, in pun version, flabbergastered) It seemed that he wasn’t so used to any attention from more than one person at a time. It was a fun morning, because we prepared a party for him because he came back. Why people were so involved in something for a person that they don’t give two shits about I’ll never know. Anyway, it was a nice alternative to the normal class schedule. And in the middle of all of the things that people were doing, he asked who organized the whole thing. So I told him who did it (Asgore and Tori) and he looked a bit disappointed. He asked if I did any of it and I told him that I didn’t even know they were planning it. That part was strange, but it was an overall great day at school.

**Notes for the Chapter:**

> down


	11. September 26 Thurs.-28 Sat. 20XX

**Summary for the Chapter:**

> idk

**Notes for the Chapter:**

> this was originally written in a google doc and BloomyTimes (ima refer to her as paper from now on, k?) commented in the last sentence “ lmao absofuckinglutely not”

September 26 Thurs.-28 Sat. 20XX

We had a teacher in-service day on Thursday and Friday, so we didn't have school. Grillby and I just hung around, sometimes at his place, sometimes at mine. I got bored once and started to use my bone attack on the snow so that it would make some nice patterns in it. Grillby told me to bring one close to him, so even though I was worried, I did. He heated the bone and then told me that in some places the snow would refreeze into snow. Using that, we made some cool designs in the snow together. While we were doing this, our hands brushed by each other. We blushed, for no apparent reason. I mean we’re just friends… right?


	12. September 29th, Saturday 20XX

**Summary for the Chapter:**

> gaster knows that sans is gay for a certain flame

September 29th, Saturday 20XX

Today Gaster had to bring me and Papy to the royal lab. He didn’t even let me bring my phone. And when I groaned he jokingly said wow, so my younger brother is gay for a flame. I punched him for that, but I didn’t exactly deny it either. Am I? Well, it sounds like Gaster is done burning dinner so I better get going！I’ll write later.

**Notes for the Chapter:**

> did anyone notice that they were being slowly rick rolled?


	13. September 30th, Sunday 20XX

**Summary for the Chapter:**

> grillby finally confesses and sans doesnt *technically* respond
> 
> also in which i realized that i needed longer chapters, but a lot of it was pre-written so i cant do anything about it.

September 30th, Sunday 20XX

I spent the whole day after school in Waterfall, just relaxing with the echo flowers when I hear Undyne’s voice behind me. She says, so Sans, where’s your boyfriend? Or did he get sick again? And then suddenly I hear Grillby’s voice saying no, we’re not dating and I’m not sick. At least not yet. And HOLY FUCK, HOW DID HE FIND ME HERE. I have no idea why he came to Waterfall, when it could be potentially dangerous for him. It was unexpected. Everyone and everything in that place and time was unexpected, even myself as weird as it sounds. She left eventually, when she realized that we were not going to give in to her teasing. And so we just sat there, underneath the stars of the underground and underneath the blanket of silence that covered that moment. It was perfect. Then, he said something. He said, look if you reject me, could we still be friends? I must of looked fucking confused, because he continued, I don’t like you as just a friend. I like you… as more than that. I didn’t know how to respond. So I didn’t. I just kissed him softly and continued to look at the stars.

**Notes for the Chapter:**

> antidisestablishmentarianism


	14. October Part 1: Going to the Roof

**Summary for the Chapter:**

> this is october. i might make it a two parter (im definitely going to make it a two parter) also, paper, as you can see i have changed a few things

**Notes for the Chapter:**

> grillby: do you like me?  
> sans: ...  
> grillby: *nervous sweating*  
> sans: HELL YEAH I DO  
> (that was just meh brain doing... something idk)

Grillby pov  
October

“Hey, Grillby, wake up! We’ve been here so long that we fell asleep.” Sans’ voice slowly woke him up. He tried to remember why he was in Waterfall and why he fell asleep there when the memories from the previous night came rushing back. He had confessed his feelings for Sans the night before, and had gotten no answer. Just a kiss. Which could have been an answer, but perhaps wasn’t.  
“Hey, um about last night…”  
“Yeah?”  
“My memory isn’t that good. Did you… reject me?”  
“No. I mean, if you were drunk or something and you just said that, then I’m sorry for making things awkward.”  
“Actually, I’ve been wanting to tell you that for a while.”  
Sans blushed and looked away. Grillby decided to grab his hand.  
“So, um. Do you want to be more than just friends?”  
“Of course, you idiot.”

《～。「t i m e s k i p 」。～》

It had been 2 days since Grillby confessed his feelings for Sans. Nearly everyone knew about them.  
“You damn nerds. I told you guys that you would fall for each other.”

“well,then, let us return the favor. let’s see… how about alphys?”

Undyne’s blush when they mentioned Alphys was unmistakable, but there was something behind that too. Grillby took note and decided to ask about that later.

“ Well, anyway, did you guys hear the news”

“What news?”

“Jerry hanged himself yesterday in the boys bathroom. We might have an assembly about suicide and bullying today.”

“why bullying though? sure everyone hated jerry, but no one told him to go and off himself”

“Well apparently people were telling him that on the internet. The fucking cowards.”

“Anyway, I’m telling you guys so that you can skip along with me, Alphys, Toriel, and Asgore. Maybe you two could go to the roof and fool around~”

Grillby was taken aback by her bluntness, and it seemed that Sans was too. Grillby’s flames were hotter and blue tinged, and Sans’s entire face was blue as well. Hell, the most they had done together was kiss and hold hands, they weren’t about to go and fuck each other so early on. Or were they?

~~yes, yes they are~~

**Notes for the Chapter:**

> floccinaucinihilipilification
> 
> also im not quite sure what happened to the chapter when i was copying and pasting it. it looks weird  
> (nvm i fixed it)


	15. October Part 2: The Fluff Ending

**Summary for the Chapter:**

> one ending to october. the true ending is smut but i know not all people are sinners (unlike me), so i made this.

**Notes for the Chapter:**

> f l u f f  
> :3

But they went to the roof anyway, giving them some privacy to relax. It had been quite a tiring day, after all.  
When they made it up to the roof, they got a nice view of the nearby twinkling rocks in Waterfall, which resembled stars. Truly a stunning sight, in Sans’s opinion. They sat together peacefully, the smaller’s head leaning on Grillby’s shoulder. It was absolutely quiet, in which they had no intent to change anything about it.

[a/n i stole that paragraph from paper]

Grillby decided to look over at Sans, and to his surprise, Sans was looking at him as well. They looked away, maybe in embarrassment, maybe because of surprise. Then Grillby grabbed Sans’ hand, and while at first he was startled, he leaned into Grillby. They stayed like that for a long time, not moving or talking, just holding on to each other and watching the stars. After a while, they went back down from the roof and while their friends traded stories about what they did, they simply listened and nodded when appropriate.

“-hat did you guys do?”

“huh?”

“Oh we didn’t do much. Just looked at the stars”

“Really? Sans looks like he’s not entirely here, and Grillby, you’re talking quieter than usual.”

“...”

“Its fine, if they don’t want to talk about it, they don’t have to”

“thanks tori”

“No problem Sans”

~~does toriel like sans? or does she like asgore?~~

**Notes for the Chapter:**

> Hippopotomonstrosesquippedalio-phobia  
> also should i make longer chapters? because everything after this is not pre-written, so i need to know so i can adjust my writing if i need to. or maybe you guys like lots of short chapters over a few long chapters. idk. thats why im asking.


	16. just a quick a/n

**Summary for the Chapter:**

> like the title says

ok i’m sorry for not updating in a long time, but someone else is writing the smut and they’re busy so it may take some time to be updated. i’m sorry.  
-kris  
(also once that’s done i’m going to update every tuesday)


	17. October Part Two: The Smut Ending

**Summary for the Chapter:**

> holy shit finally

**A few minutes into their little stargazing, Grillby noticed the loud silence and decided a change of scenery. He looked down at his small boyfriend. His eye lights and sockets focused on the twinkling rocks above and only the twinkling rocks, with a perfect smile. He was absolutely adorable. This made Grillby wonder… could he get Sans to focus on something else for a bit? Let’s see if he was up for it.**

**With that, the pyro carefully took Sans’s hands, which slightly alarmed the smaller. The elemental then proceeded to kiss each one of the skeleton’s small and tender knuckles. The gesture did result in exactly what the fire monster wanted and Sans flushed in embarrassment. Grillby took that as a chance to cup Sans’s cheek and pull the small skeleton in for a tender kiss.**

**That kiss had soon turned into an intense make-out session. Tongues swerving at each other in perfect sync. Grillby decided to take it up another notch and slyly, drove his free hand up his boyfriend’s shirt and gently used his fiery digits to pluck at all the ribs in Sans’s rib cage. Making him shudder into the heated touch, and fall onto his back. Sans started to pant into the kiss, which encouraged the fire monster to do more. He used his free hand again to hold Sans’s hand, to silently ask for permission. He accepted.**

**Grillby’s hand then proceeded to drift back underneath San’s shirt, and carefully grip his cyan soul. Sans let out a pleasurable whine, as his boyfriend began stroking and rubbing his sensitive soul, stimulating him enough as a tease, but not enough for him to be overwhelmed just yet.**

**Grilby shifted so his knee could hold him up, and his other hand that was holding him up before could toy with his lover’s pelvic girdle.**

**Grillby lowered his head so he could nibble and suck on Sans’s cervical vertebrae. The stimulation was already getting to him. Sans slick, blue, magic snapped into place in his pelvis, right above his coccyx. As soon as the throbbing pussy was in Grillby’s view, he kissed his boyfriend deeply, while taking his hand and flirting with the lips of Sans’s entrance.**

**Feeling the amazing touches to his pussy, Sans keened, moaning more into the kiss. The delicious sounds that the smaller was making, encouraged Grillby to do more. He took two fingers and gently dived them into his lover’s entrance. Thrusting in at a pace that could’ve made Sans cum right there and then.**

**The elemental kept his thrusts in sync with the toying of the soul behind Sans’s sternum. The cyan soul becoming more liquidy and gooey on it’s surface, replicating some sort of pre-cum, meaning the smaller was going to cum soon, most likely. The inferno added a third finger to the thrusting of Sans’s pussy, rubbing into his clit, and making him tremble head to toe.**

**Then the wave of euphoria came, and San’s jolted at the feeling, making Grillby gently pull away from their kiss. As the skeleton was getting down from his high, his boyfriend slowly took his fingers out from beneath his shorts, making a wet squelching sound when doing so. Sans’s goo was all over the elemental’s fingers, so he licked it all up, finger by finger, which made Sans flush in both embarrassment and adortion.**

**The small skeleton managed to lift himself up so he could sit upright, to press a chaste kiss to his hot boyfriend.**

**They truly loved each other.**

**a/n sorry that it’s all in bold i didn’t feel like changing it. whatever. anyway, now all the posts will be on tuesdays.**

**Notes for the Chapter:**

> thanks to paper (BloomyTimes) for writing this. i’m shit at smut so yeah.


	18. i’m sorry

**Summary for the Chapter:**

> i’m a terrible fucking person

so  
i haven’t updated  
i’m sorry  
i’ll try, but i can’t promise  
i’m more active on wattpad though, so i might move it there  
but i’m (still) sorry for forgetting about ao3 and this fanfic.  
\- this shitty person, a.k.a. the author


End file.
